Many industrial and commercial processes and some consumer activities benefit from thoroughly cleaning the surface of an article prior to application of the article for its intended end use or prior to clearing the article for further processing or disposal. Examples of such applications are cleaning articles prior to bonding them or applying a surface finish, removing hazardous surface contamination from articles prior to their exposure to humans or other living organisms, and polishing surfaces for beauty or clarity. Over the years many forms of paper, fabric, and film utility wipes have been developed to assist in such cleaning processes. Some utility media incorporate a tackifier to assist in removing contamination from a surface being cleaned and in holding any minute solid particles or trace liquids on the cleaning medium as it swipes the surface of the article being cleaned. Many tackifiers are inherently sticky substances, and cleaning an article using a medium that incorporates such sticky substances may be difficult if the tackifier in a cleaning medium causes the cleaning medium to stick to the article being cleaned. To overcome this problem, some utility media add a lubricant or a release agent or similar chemical to the medium in order to decrease friction between the cleaning medium and the article being cleaned. However, such additives may reduce the overall cleaning efficiency of the cleaning medium and in some cases leave an unwanted residue on the article being cleaned.
Among the difficulties facing manufacturers of any consumer or industrial product is that as manufacturing technologies improve, manufacturing tolerances and safety standards become increasingly tighter and cleanliness requirements become more demanding. For example, it is not uncommon for contamination limits to be set at fractions of micrograms per hundred square centimeters. One difficulty in achieving these levels is that as cleaning products and processes become more efficient in removing original contamination from an article, the cleaning products and processes may themselves contribute to the final contamination level of the article because of residues of chemicals used in the medium that are left on the cleaned article. What are needed therefore are improved cleaning media that entrap and remove harmful contamination from the surface of an article to be cleaned without leaving residue from materials incorporated into the cleaning medium. Also, because these media are typically discarded after a single use or a small number of uses, what are further needed are inexpensive and simple methods for manufacturing high performance cleaning media.
There are also many industrial, commercial and consumer applications for filtration of contaminants from a gaseous fluid flow. Examples are furnace filters, clean-room filters, glove-box filters, and breathing mask filters. In many of these applications it is desirable to not only prevent the passage of contamination beyond the filtration point but to also entrap the contamination in a manner that diminishes the inadvertent release of filtered contaminants during operation and during maintenance when the filter is replaced. In some applications it may be desirable to electrostatically attract contaminants in a gaseous fluid flow stream without employing an electronic static generator. While various filtration systems have been developed to address some of these needs, there are many applications that may benefit from an inexpensive filter having improved filtration properties combined with reduced resistance to fluid flow.